This is a long-term project to maintain surveillance on the current state of knowledge of the effects of environmental and other chemical agents on the human body by means of literature searches and such other information as may become available in order to provide advice to Government and other agencies on specific environmental hazards and from time to time to review the current state of knowledge on individual chemical agents. A pilot study is being undertaken to see how far it is feasible to prepare an index of toxicological symptoms and diseases to assist in the differential diagnosis of obscure outbreaks of disease considered likely to be of toxicological origin.